Gemstones

Gemstones

Contributors in Gemstones

Gemstones

The term used to designate a family of gemstones. For example, corundum is a species that contains the varieties sapphire and ruby. The Quartz family contains amethyst, citrine, and chalcedony, to ...

Sheen

Fashion; General jewelry

This effect resembles luster, and is caused by light reflection from inclusions or texture inside the gem. lustre is light reflected from the surface of the gem and sheen is reflection from inside ...

Side stone

Fashion; General jewelry

Side stones are set around or beside the centre stone in a jewellery setting.

Single refraction

Fashion; General jewelry

Most gemstones are doubly refractive -- they have 2 refractive indices. Only a few gemstones have a single refractive index, specifically diamond, spinel and garnet. See also Birefringence.

Double refraction

Fashion; General jewelry

The ability of most gems to split rays of light into two rays.

Doublet

Fashion; General jewelry

Doublet is a gemstone composed of valuable gemstone material in combination with other materials. It is found most often in opal, where an opal doublet contains a slice of opal glued to common opal, ...